Automatic rouge feed for buffing machines



Feb. 9, 1937. R. s. SPERRY AUTOMATIC ROUGE FEED FOR BUFFING MACHINESFiled May 25, 1955 5 Sheets-Sheet 1 T0 2 w PRESSURE LINE TO HIGHPRESSURE LINE 1 I @IIIUIIIL INVENTOR 10 R r aspen '1 2?? ATT Feb. 9,1937. R. s. SPERRY AUTOMATIC ROUGE FEED FOR BUFFING MACHINES Filed May25,

1935 3 Sheets-Sheet 2 INVNTOR Roger 5.8pervy.

ATTO EY Feb. 9, 1937. s, SPERRY 2,070,322

AUTOMATIC ROUGE FEED FOR BUFFING MACHINES Filed May 25, 1935 3Sheets-Sheet 3 3 l m I INVENTOR F 7 .T By Roger 3-5pm? 133 A 7 p 137 R136 132 26 136 ATTO Y Patented Feb. 9, 1937 PATENT OFFICE" 4 2,070,322AUTOMATIC ROUGE FEED FOB BUFFING .HACHINES Roger 8. Sperry, ,Waterbury,Donn,

The Packer Machine Com, a corporation of Connecticut aallgnorto den,

Application May 25, 1985, Serial No. 28,458

16 Claims- (Ol. 51-268) This invention relates to bumng machines, andmore particularly to an automatic mechanism for intermittently applyingabradant to a rotating bufllng or polishing wheel.

One object of this invention is to provide an automatic mechanism of theabove nature in which the abradant in the form of a solid block or brickis successively reciprocated and forced against the bufllng wheel atregular intervals.

' A further object is to provide a mechanism of the above nature forapplying abrasive to a bulling wheel in which the block of abrasive isadvanced farther on each successive stroke in -order to compensate forthe material removed from ti: bllock of abrasive by contact with thebufllng w ee A further object is to provide a mechanism of the abovenature in which the abrasive block is normally urged away from thebufllng wheel by low pressure pneumatic means and is. driven forwardlyinto contact with said wheel by automatically "actuated high pressurepneumatic.

means which overbalances said low pressure means. v i

A further object is to provide an abradant feeding machine of the abovenature in which the reciprocating abradant carriage is connected to apiston rod operating in a compressed air cylinder, the supply of airbeing controlled by cams mounted on the edge of a slowly rotating workcarrying table.

A further object is to provide an abradant reed machine of the abovenature in which the abradant carriage is provided with a pair ofgripping plates for adjustably clamping about the sides of the abradantblock, one of said platesbeing laterally adjustable to accommodatevarious sizes of blocks and both plates being simultaneously movablelaterally to centralize the block with respect to the supporting table.

A further object is to provide an abradant feeding machine of the abovenature in which the carriage is detachably connected to a threadedreciprocating plunger red by means of a pair of jaws which may bemanually released from said threaded rod for permitting the carriage tobe quickly returned to its initial position when the block of abrasivehas been used up.

A further object is to provide an abradant feed mechanism of the abovenature which will be comparatively simple in construction, inexpensiveto manufacture, economical of abrasive and bufilng wheels, easy toinstall and manipulate,

time and labor saving, compact, and very efficient and durable in use.

With these and other objects in view, there has been illustrated on theaccompanying drawings, one form in which the invention may beconveniently embodied in practice.

In the drawings:

Fig. 1 represents a perspective view of the abradant feeding mechanismas it appears when installed upon a conventional buiilng machine.

Fig. 2 is a-vertical sectional view taken through the pneumatic controlvalve and the edge of the 10 rotating work carrying table.

Fig. 3 is a top plan view of the pneumatic control valve.

Fig. 4 is a horizontal sectional view of the same taken along the line4-4 of Fig. 2,1ooking in the direction of the arrows.

Fig. 5 is a top plan view of the abradant feeding mechanism, per se.

Fig. 6 is a front elevation of the same, partly in section, and withportions broken away to ratchet feeding mechanism for advancing theblock carriage farther on each successive stroke to compensate for theamount of abrasive worn from the block.

Fig. 11 is a similar exploded view of the split clamping jaws forconnecting the block carriage to the threaded section of the plungershaft, and showing the means for enabling the carriage to be quicklyreleased therefrom.

Fig. 12 is a detail perspective view of the guide bracket for' slidablysupporting the clamping 40 jaws.

Referring now to the drawings in which like reference numerals denotecorresponding parts throughout the several views, the numeral Illindicates the top of a stationary table above which 5 is a slowlyrotating work carrying platform I l. Journaled upon the platform II area plurality of rapidly revolving vertical spindles I2 having workholding heads l3 for supporting articles M to be buifed. The revolvingspindles I! are adapted to be slowly carried by the rotation of theplatform ll into the path of one or more bufling wheels l5 (only onebeing shown in the drawings) Located at right-angles to the axis of thebuflapairofbolts 22 having threaded engagement in the platform |8,--thisconstruction being such that the rouge carriage supporting table 6 maybe moved longitudinally with respect to the platform It! and clamped inany desired adjusted position by means of said bolt 22.

Reciprocating rouge holding carriage A cake 23 of abradantbufiingmaterial in the shape of a rectangular brick or block shown in 'dot anddash lines in Figs. 1,5 and e is adapted to rest upon the table l6, andis adapted to slide along the top thereof into [and out of engagementwith the periphery'of the adjacent bufling wheel |5. The rear end of therouge block 23 abuts against a rouge carriage 24 having a pair oflaterally clamping p1ates 25 and 26 slidably fitted therein, said platesbeing, adapted to tightly grip the opposite sides of the rear end of therouge block 23. v

The rouge carriage '24 extends transversely across the top of thesupporting table l6, and is provided with an integral rearwardlyextending-horizontal flat section 240 having a depend-' ing elongatedtongue 21 having slidable engagement in a longitudinal guiding slot 28extending centrally along the table I6.

Located directly underneath the carriage 24 of the table I6 is a slidingjaw gnide block or bracket 29 having a rearwardly extending section 39provided with an upwardly formed tongue 3| adapted to fit the slot 28and engage the depending tongue 21 of the section-24a. The carriage 24and guide bracket 29 are adapted to be held together on opposite sidesof the table l6 by means of a pair of cap screws 32 passing throughsuitable apertures in the section 2411 and screwed into correspondingtapped holes 33 provided in the section 39 of the guide bracket 29 (seeFig. 12).

The assembled carriage 24 and guide bracket ,29 are adapted to bereciprocated along the table 6 by means of a plunger rod 34 locatedunder said table. The forward end of the plunger rod 34 is slidablysupported in a hanger bearing 35 made rigid to the underside of thetable l6, and the rear end of said plunger rod is supported in acylinder 36 to be described later. The plunger rod 34 is provided withan intermediate threaded section 31 which is adapted to be connected tothe reciprocating carriage 24 by means of a pair of cooperating jaws 38and 39 having semi-cy-- lindrical threaded sections 49 and 4| forengaging upon opposite sides of the threaded section 31 of the pistonrod 34. The jaws 38 and 39 are adapted to slide transversely in theguide bracket 29 in a pair of opposed parallel guideways 42 providedtherein.

In order to uncouple the jaws 38 and 39 from the threaded section 31 ofthe plunger rod 34 so that the carriage 24 may be moved independently ofsaid rod 34, said jaws are provided with a pair of upstanding guide pins43 and 44 which are adapted to engage in a pair of arcuate cam grooves45 and 46 formed in a disc member 41.

As clearly shown in Figs. 8 and 12, the disc member 41 is mounted tooscillate in a circular aperture. 48 provided in the sliding jaw bracket29, and is provided with an upwardly extending shaft 49 journaled in asuitable vertical hole 49a provided in the carriage 24. The shaft 49extends above the carriage 24 and is provided at its upper end with ahand wheel 50.

It is to be noted from Fig. 11 that the arcuate slots 45 and 46 areeccentrically positioned with respect to the axis of the disc member 41so that when the hand wheel 50 is turned, the jaws 38 and 39 will bespread apart for disengaging them from the threaded sections 31. of theplunger rod. This will allow the carriage 24 to be moved independentlyof the plunger rod 34.

Compressed air cylinder In order to cause the plunger rod 34 to bereciprocated for alternately forcing the rouge block against the buiflngwheel and then retracting said block therefrom, compressed air will beadmitted to opposite sides of the cylinder 36 previously mentioned. Thecylinder 36 comprises a cylindrical housing 5| having integral flatoppositely extending flanges 5|a on its' upper side by means of whichsaid housing 5| may be attached to the underside of the rouge carriagesupporting table l6 adjacent the rear end thereof by means of cap screws52. The opposite ends of the cylindrical housing 5| .are adapted to beclosed by means of a pair of front and rear end caps 53 and 54, thusproviding a tightly sealed. piston chamber 55 within the housing 5|.

. 'I'hefront end cap 53 is provided with an axial bore 56 surroundingtheplunger shaft 34 and rendered leak-proof by means of a threaded glandmember 51 and a packing ring 58. The rear extremity of the shaft isprovided with a reduced section 59 for receiving a piston head 60comprising a pair of opposed cupped leather washers 6|. 6| held betweena central metal spacing washer 62 and a pair of end collars 63, 63. Thewashers 6|, 6| and the collars 63, 63 are adapted to be tightly clampedagainst a shoulder -I34 formed at the-junction ofthe reduced section 59and the shaft 34 by means of a pair of locking nuts 65.

In order to admit low pressure and high pressure air to the oppositesides'of the piston head 60 respectively, the end caps 53 and 54 arepro- 4 vided with ports 66 and 61 opening into the chamber 55. The ports66 and 61 have nipples 68 and 69 threadedly screwed therein, saidnipples being connected respectively to a low pressure hose line 16 anda high pressure hose line 1|, the latter pipe 5 1| being connected to apneumatic control valve 12 located on the bufiing machine.

Pneumatic control value The pneumatic control valve 12 comprises a qcircular shaped cover member 13 having a rearwardly extending angularbracket 14 attached to a spacing block 15, which in turn is securedrigidly to the depending side wall of theblimng table l6 (see Figs. 1and 2). A hollow flanged body a member 16 having a stepped lower sectionis secured to the underside of the cover member 13 by means of capscrews 11, a valve chamber 18 being enclosed therebetween.

The cover member 13 is provided with three 7 radial semi-cylindricalraised bosses 19, and

8| on its top siu'face. The outer ends of the bosses 19 and 88 areprovided with tapped holes 192 and 802, respectively, which communicateswith a pair or reducedangularorifices 19b and Z.

9911 leading into the valve chamber 10. Anlpple 92 is screwed into thetapped hole 19a and is adapted to receive one end'of the high pressureline". The other tapped hole 990 o! the boss 99 is fitted with an elbownipple 93 which is di-. rected downwardly and is open to the atmosphereto serve as an exhaust port for the control valve 12.

The bottom of the stepped body member 19 is provided with a tapped port94 for receiving a nipple 99,-which is connected to a hose feed line 96leading to any convenient supply of compressed air or other suitableoperating fluid under high pressure. Ordinarily-the high pressure line'99 will be supplied with air at about 80 pounds per square inch, whilethe pressure in the low pressure line 19 will preferably be maintainedat about 25 pounds per square inch.

The center of the cover member 13 is provided with a hollow upstandingboss 91 in which is journaled a valve-operating shaft 99 having attachedto its lower end a valve sector 99, as by means of a transverse pin 99(see Figs. 2 and 4). The top surface of the valve sector 99 is providedwith a pair of depressed arcuate grooves 9| and 92, the former groovebeing longer than the latter. The groove 9I normally connects theorifice 1917 leading to the pipe 1|, with the orifice 99b leading to theexhaust nipple 99. The short groove 92 is provided with a verticalpassage 99 leading to the chamber 19.

In order to cause the control valve 12 to. apply rouge to the bumngwheel I9 during the interval between the bufling operations thereof. theoper-..

ating shaft 99 is provided at its upper end with a lateral arm 94 havinga bifurcated free end 95 for embracing a roller 96held in place by meansof a vertical pivotpin 91. The pivot pin 91 is provided with 9.depending enlarged extension 99 which is normally held by a coiledspring 99 against a raised fin I99, forming an integral part of thecover member 13. The depending extension 99 is provided with acircumferential groove I9I for receiving one end of the helical spring99 while the opposite end of said spring is attached to the inturnedhorizontal end I 92 of an L-shaped rod I93 fitting in a hole I 94provided in the raised boss 9| of the cover 13.

A plurality of cam trip blocks I95 (one only being shown on thedrawings) are secured on the periphery of the rotating work platform II.Each trip block I95 is provided with an outwardly extendingpyramid-shaped nose I96 which engages the roller 96 by a cam action, andis adapted to oscillate the valve sector 99 in a coimter-clockwisedirection. This will bring the short arcuate slot 92 into registry withthe orifice 19b, allowing air under high pressure to rush into the hoseline H and be admitted to the right-hand or outer end of the pistoncylinder 36, as viewed in Figs. 1 and 6. The piston head will thus beforced to the left causing the rouge block 23 to be forcibly applied tothe edge of the revolving bufling wheel. When the roller 96 passesbeyond the trip block I95, the spring 99 will immediately return thesector 99 to its original position, allowing the high pressure air toescape from the outer end of the cylinder and permitting the abrasiveblock to be retracted from the bufling wheel by the low pressure airwhich is exerted constantly on the left-hand side of the piston.

Compensating mechanism In order to compensate for the amount of abrasiveremoved from the rouge block 23 each time.

it engages the bufling wheel I9, provision is made of an L-shapedbracket-l91secured adjacent the front edge of the table I9 and dependingdownwardly therefrom. The rear wall of the bracket I91 carries anadjustable loop-shaped box cam I99 having an integral'laterallyextending trunnion I99 reduced and threaded at its extremity III. Thetrunnion I99 is journaled in a horizontal aperture III provided in thevertical wall -of the L-shaped bracket ML The box cam I99 a nut H2 and awasher II3 mounted on the threaded end of the trunnion I99 outside thebracket I91.

.The rear end of the box cam I99 is provided with an integral tapped lugII4 for receiving a binding screw II5 which projects through and isslidable in an arcuate slot II9 provided in the depending wall of thebracket I91. This construction permits the box cam I99 to be manuallytilted to any desired adjusted angular position, after which the cam maybe locked by manipulating a head Ilia on the end of said screw I I6.

In order to visually indicate the exact angular position of the box camI99, provision is made of a small angular scale plate II1 attached tothe left side edge of the bracket member I91, as viewed in Fig. 6. Theplate H1 is provided with a graduated scale I I9, which is adapted to beread with reference to a fixed indicating line H9 located on theadjacent exposed end of the box cam I99.

Directly in back of the bracket I91 and rigidly mounted upon the plungerrod 34 is a ratchet wheel I29 (see Figs. 7,8 and 10), and mounted on therod 34 adjacent the ratchet wheel 29 is a bellcrank lever IZI. Therearwardly extending arm I2 In of said lever is provided with a pivotedpawl I22 which is adapted to engage with the teeth of the ratchet wheelI29. The pawl I22v is urged against the ratchet wheel I29 at all timesby means of a small helical tension spring I23 connected at its ends toa pair of pins I24 and I2! mounted on the pawl I22 and the lever I2I,respectively. The opposite end of the arm I2Ib of the bell-crank leverI2I carries a transverse follower wheel I26 which is adapted to ridewithin the box cam I99.

In order to hold/the ratchet wheel I29 against reverse rotation,provision is made of a relatively broad horizontalgflat leaf-spring I21attached to the lower edge of the bracket I91 by means of screws I28and? projecting inwardly therefrom. The inner free 'end of the springI21 is provided with an upturned bent extremity I29 which is adapted toengage with the ratchet wheel I29.

Rouge clamping jaws The adjustable rouge clamping jaws 25 and 26 areprovided with integral tongued guide blocks I3I and I32, which areadapted to slide in a T- shaped guide slot I33 extending across theentire front face of the carriage member 24. The guide block I3I of therear clamping plate 25 is provided with a horizontal hole I34 in whichis rotatably journaled a reduced section I35 of a horizontal adjustingscrew I36. The rear end-of the reduced section I35 has a rigid collarmember I31 to prevent axial movement of the adjusting screw I36 withrespect to the clamping plate 25. The forward end of the adjusting screwI36 is provided with a rigid winged turning handle I39. A hollow sectionI39 is provided adjacent the T- shaped slot I33, and said section isopen at the rear of the carriage I24 to receive a rearwardly projectinglug I40 forming an integral part of the tongued block I3I. The lug I49is provided with a tapped hole Illa for receiving a clamp centralizingscrew I4I, extending forwardly to the front of the carriage and beingprovided with a kerfed head I42. An integral thrust collar. I43 isprovided between the head I42 and the threaded section of the screw I,said collar I43 being seated in the base of a countersunk socket I44 andheld against axial movement by means of an outer bushing I45 tightlyfitting in said countersunk socket I44.

It will be noted from the above construction that by merely turning thewinged handle I38, the rouge block clamping plate 26 may be adjustedinwardly or outwardly in a transverse direction to accommodate varioussizes of abrasive blocks. It will also be noted that by turning thekerfed screw I H with the aid of a screw driver, the screw I36 togetherwith the clamping plates 25 and 26 will be moved as a unit to anydesired adjusted position with respect to the bumng wheel.

As best shown in Fig. 1, the adjacent faces of the rouge block engagingplates 25 and 26 may be provided with knurled or roughened grippingareas.

In order to protect the working mechanism of the abradant feed machinefrom the dust created by the bufiing machine, provision is made of anangular shaped dust guard I46 located at the rear of the supportingtable. I I6. The dust guard I46 is held in position under the table I6by angle brackets I41.

Dust is also excluded from the rear of the slot I Operation In theoperation of the rouge feeding mechanism, whenever one of the cam tripblocks I05 carried by the rotating table II engages the roller 96carried by the lateral arm 94 of the control valve I2, the valve sector89 will be swung in a counter-clockwise direction as viewed in Figs. 3

v and 4. This will connect the pipe line 86 to the hose line II, andadmit compressed air under high pressure at the right of the piston head60, causing the plunger rod 34 to move forwardly in the cylinder 36 asfar as it will go. The forward thrust of the plunger rod 34 will carrythe carriage 24 along the table I6 and will cause the rouge block 23 tostrike the face of the-bufling wheel I5 and apply "the desired amount ofrouge thereto.

As soon as the trip block I95 has passed the roller 96, the lateral arm94 will be moved back to its normal position by thehelical spring 99,and in this position the valve sector 39 will again connect the orifice191) with the orifice 30b through the elongated arcuate groove 9|. Thiswill permit the high pressure" compressed air block by its contact withthe bufllng wheel on each forward thrust of the plunger rod 34, the

follower wheel I26 on the end of the ratchet op-- erating bell-cranklever I2I will be caused to ride forwardly in the cam slot of the boxcam I08, and consequently will be forced downwardly due to theinclination of said box cam. This action will cause the bell-crank lever|2I to tilt about the axis of the shaft 34 and twist said shaftin acounter-clockwise direction with it by means of the ratchet wheel I20-and pawl connection I 22. The split jaws attached to the rouge blockcarriage 24 will thus be moved forwardly the required distance.

It will be understood that a greater or lesser degree of compensatingmovement on the part of the carriage 24 may be readily accomplished bymerely adjusting the box cam I03 to different angular positions withinthe limits of the arcuate slot II6. This is performed by manipulatingthe binding screw I I 5 to the desired extent.

While there has been disclosed in this specification one form in whichthe invention may be embodied, it is to be understood that this form isshown for the purpose of illustration only, and that the invention isnot to be limited to the specific disclosure but may be modified andembodied in various other forms without departing from its spirit. Inshort, the invention includes all the modifications and embodimentscoming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, andfor which it is desired to secure Letters Patent is:

1. In a mechanism for automatically feeding abrasive to a bufiing wheel,a holder for a cake of abradant material, a plunger rod connected tosaid holder, a cylinder, said plunger rod carrying a piston operable insaid cylinder, means for constantly supplying air at low pressure tosaid cylinder on the side of said piston adjacent said holder tonormally keep said abradant cake away from said buifing wheel, means forsupplying air at a high pressure for a short period of time to saidcylinder on the other side of said piston to overbalance the lowpressure and cause said cake to move forward and strike said buffingwheel.

2. In a mechanism for automatically feeding abrasive to a bufiing wheel,a holder for a cake of abradant material, a plunger rod connected tosaid holder, a cylinder, said plunger rod carrying a piston operable insaid cylinder, means for supplying air at low pressure to said cylinderon one side of said piston to normally keep said abradant cake away fromsaid buiiing wheel, means for periodically supplying air at a higherpressure to said cylinder on the other side of said piston tooverbalance the low pressure and cause said cake to move forward andstrike said buffing wheel.

3. In a mechanism for automatically feeding abrasive to a bufiing wheel,a holder for a cake of abradant material, a plunger rod detachablyconnected to said holder, a compressed air cylinder, a piston operablein-said cylinder and connected to one end of said rod, means forsupplying air at low pressure to one end of said cylinder for pressingupon said piston to normally keep said abradant cake away from saidbufling wheel, means for supplying air at a higherpressure to theopposite side of said cylinder to move said plunger rod forwardly andcause said abradant to strike said bufllng wheel, and valve means forperiodically connecting said high pressure air supply to said cylinder.

4. In a mechanism for automatically feeding abrasive to a bufllng wheel,a movable work carrying table, a holder for abradant material, a plungerrod connected to said holder, pneumatic means for normally holding saidplunger rod away from said buillng wheel, pneumatic means for forcingsaid plunger toward said bumng wheel to cause said material to beapplied to said wheel, a valve for controlling the operation of saidsecond mentioned pneumatic means, said valve being oper ated by themovement of said table.

5. In a mechanism for automatically feeding abrasive to a buillng wheel,a movable work carrying table, a holder for abradant material, a plungerrod connected to said holder, pneumatic means for normally urging saidplunger rod away from said bufling wheel, pneumatic means forintermittently forcing said plunger toward said buifing wheel to causesaid abradant to be applied to said wheel, a valve for controlling theoperation of said second mentioned pneumatic means, said valve beingoperated by the movement of said table, and means on said valve torender inoperative said second mentioned pneumatic means at the end ofthe forward stroke of said plunger rod.

6. In a mechanism for automatically feeding abrasive to a bufling wheel,a movable work carryin'g table, a holder for abradant material, aplunger rod connected to said holder, means for normally urging saidplunger rod away from said bufllng wheel, pneumatic means for forcingsaid plunger toward said buffing wheel to cause said abradant to beapplied to said wheel, a valve for controlling the operation of saidpneumatic means, said valve being operated by the movement of saidtable, and means on said valve to render inoperative said pneumaticmeans at the end of the forward stroke of said plunger rod.

'7. In a mechanism for automatically feeding abrasive to a buflingwheel, a stationary platform, a carriage member slidable on saidplatform for holding abradant material, a slidable plunger rod mountedunderneath said platform and connected to said carriage, means fornormally urging said plunger rod away from said bufiing wheel, andperiodically operated pneumatic means for overbalancing said firstmentioned means and moving said rod in the opposite direction to causesaid cake to be forcibly applied to said bufilng wheel.

8. In a mechanism for automatically feeding abrasive to a bufilng wheel,a stationary platform mounted adjacent said buffing wheel, an abrasiveholding carriage slidably mounted on said platform and movable towardand away from said buiilng wheel, a slidable plunger rod mountedunderneath said platform and connected to said carriage, pneumatic meansfor moving said plunger rod to apply abrasive to said bufllng wheel, andpneumatic means for thereafter moving said rod in the opposite directionaway from said bufling wheel.

9. In a mechanism for automatically feeding abrasive to a buifing wheel,a platform, a holder for abrasive slidably mounted on said platform, aslidable plunger screw mounted underneath said platform, means forthreadedly connecting said screw to said holder, pneumatic means forperiodically reciprocating said screw to carry said abrasive into andout of contact with said buillng wheel, and means for slightly twistingsaid screw at each stroke thereof to cause said holder to be movedforwardly an increasingly greater amount to compensate for the materialapplied to said buffing wheel.

10. In a mechanism for automatically feeding abrasive to a bufflngwheel, a platform, a holder for abrasive slidably mounted on saidplatform,

a slidable plunger screw mounted underneath said platform, means fordetachably and threadedly connecting said screw to said holder, meansfor periodically reciprocating said screw to carry said abrasive intoand out of contact with said bufllng wheel, and means for slightlytwisting said screw at each stroke thereof to cause said holder to bemoved forwardly an increasingly greater amount to' compensate for thematerial applied to said bufiing wheel.

11. In a mechanism for automatically feeding an abrasive material to arotating bufllng wheel, a reciprocating holder for said abrasivematerial, a plunger rod threadedly connected to said holder forperiodically applying said material to said buffing wheel, a ratchetwheel fixed to said plunger rod, a bell-crank lever journaled on saidrod, a pawl pivoted to one end of said bell-crank lever for engaging theteeth of said ratchet, cam-operated means for rocking said lever on eachforward stroke of said rod, whereby said holder will be movedprogressively farther on each successive stroke to compensate for theabrasive applied to said buffing wheel, and means to prevent rearwardrotation of said ratchet wheel.

12. In a mechanism for automatically feeding abrasive material to arotating buffing wheel, a reciprocating holder for said material, aplunger rod threadedly connected to said holder for periodically movingsaid material into and out of contact with said bufilng wheel, a ratchetwheel fixed to said plunger rod, a bell-crank lever journaled on saidrod, a pawl pivoted to one end of said bell-crank lever for engaging theteeth of said ratchet, cam-operated means for rocking said lever on eachforward stroke of the holder, whereby said holder will be moved closerand closer to said bufling wheel on successive strokes to compensate forthe abrasive applied to said bufling wheel, means to prevent rearwardrotation of said ratchet wheel, and means for adjusting saidcam-operated means to vary the amount said rod will be rocked on eachstroke.

13. In a mechanism for automatically feeding abrasive material to arotating buffing wheel, a reciprocating holder for said material, aplunger rod threadedly connected to said holder for periodically movingsaid material into and'out of contact with said buifing wheel, a ratchetwheel fixed to said plunger rod, a bell-crank lever journaled on saidrod, a pawl pivoted to one end of said bell-crank lever for engaging theteeth of said ratchet, a pivotally mounted slotted box cam embracing theother end of said lever, said cam being fixed in position, means to varythe inclination of said cam to control the rocking of said lever on eachsuccessive stroke of the holder to determine accurately the amount ofabrasive applied to said bufling wheel.

14. In a mechanism for automatically feeding an abrasive material to arotating buffing wheel, a reciprocating holder for said material, aplunger rod threadedly connected to said holder for periodically movingsaid material into and out of contact with said bufling wheel, a ratchetwheel fixed to said plunger rod, a bell-crank lever journaled on saidrod, a pawl pivoted to the teeth of said ratchet, a pivotally mountedslotted box cam embracing the other end 01' said lever, said cam beingfixed in position. means to vary the inclination of said cam to controlthe rocking of said lever on each stroke 01' the holder to determineaccurately the amount of abrasive applied tosaid bufllng wheel, andscale means to indicate the exact setting oi said cam.

15. In a mechanism for automatically feeding abrasive to a buflingwheel, a holder for abrasive material, a plunger rod connected to saidholder,

means to normally urge said rod to retracted one end of said bell-cranklever for engaging cally opened valve to connect said source to saidfluid operated means.

16. In a mechanism for automatically abrasive to a bufllng wheel, aholder for abrasive material, a plunger rod connected to said holder,means to normally urgesaid rod to retracted position, fluid operatedmeans to overbalance said retracting means and force said rod forwardlyto apply said abrasive to said buffing wheel, a source of fluidpressure, and a periodically opened valve to connect said source to saidfluid operated means, said valve also having means to exhaust said fluidat the end of the stroke of said abrasive holder to permit saidretracting means to again become eflective.

ROGER s. SPERRY.

